Process of treating and producing corrected halftone plates or metallic printing plates



Sept. 2 1924. v DI ERT PROCESS OF TREATING AND PRODUCING CORRE D HALF'I'ONE PLATES OR METALLIC PRINTING PLATES v Filed July 24, 192:4

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Patented Sept. 2, 1924.

UNITED STATES JIILIUS DIGKER'I. 0F CHICAGO ILLINOIS.

PROCESS or TREATING AND rnonocmocoaano'rnn HALrToNErnA'rEs on I METALLIC PRINTING rnATE-s.

Application filed July 24,

Be it known that I JULIUS DrcKnnig a citizen of the United States, residing in Chi cago. in the county of (look and State of Illinois, have invented certain new and useful Improvements in Processes of Treating Y and Producing Corrected Halftone Plates or Metallic Printing Pzlates, of which the, fo-l-' lowing is a specification. r E

This invention relates to an improved process of treating and producingcorrected half-tones, electrotype plates, or other metallic printing plates, and to half-tones, electrotype piatcs or other metallic printin plates made in accordance With my improved process.

It relates particularly to half-tone plates, electrotype plates or other metallic printing plates made in accordance with my improved process and having What is commonly termed and known as the makeready. in the metallic printing plate when.

com )leted and ready for use.

T e principal object of this invention is to provide a simple. economical, and efiicient process of treating and producing corrected half-tone plates, electrotype plates, or metallic printing plates, and including the process of so forming such metallic printing li odied in the printing plate or completed in the operation of completing such printing plate. so that a further operation to complete a make-ready will he, so far as possible, unnecessary, and may. in many instances. he entirely dispensed with.

Other and further objects of the invention will appear from the following description? and claims. and from the accompanying 1 drawings, which are madea part hereof. I i

The invention consists in the improved process of treating and producing'corr 'ected half-tones. electrotype plates, or metallic. printing plates herein described. and claimed, and in halt-tones, electrotype plates or other metallic printing plates made in accordance with my improved process.

In the accompanying drawings:

F igure 1 is a plan In view of a photo-1 engraving, from which an improved hailf-:

tone, eiec-trotype plate, or other metallic printing plate is to be made, or provided with a printin surface having a makere-adyi embodied in such plate and printing 1922. Serial No. 576,996.

surface, in accordance with my improved process and invention;

Fig. 2 is a similar view of a transparent sheet or proof-sheet made. from the original photo-engraring or iniage shown in Fig. 1;

Fl f. 3 is a sllllilaifiYlQtV of acompleted meta lic make-ready overlay plate or sheet made in accordance :Wit'h'my improved proccss and having, a pictorial image thereon corresponding with the picture, image or design on the original photo-engraving or picture shown in Fig. 1. hut With the highlights or high-light surfaces in the makeready overlay plate corresponding with shadow-tones inthe original photo-engrav ing or picture, and vice versa;

Fig. 4 is a similar view of a half-tone plate. electrntypaenmetallio printing plate. to he opcratednpon and impressed or made ready and completed in accordance with my improved n'ocess, and by means of the metallic make-ready overlay plate or sheet shown in Fig. 3;

Fig. 5 is a similar view showing a metallie nialzeo'cady plate. made in accordance with my process. but hynlaking a proof in in]; from the original photo-engraving di- J'Q-(ZlSIV' upon the sensitised coated surface-oi" "the metallic overlay plate" plates that the make-ready will be em-:.. 5

Fig; 6 a view in side elevation showing the transparent sheet-of 13 1g. in contact with the inked prlntmg surface of the origin-al jyhotoeugravmg, shown in Fig. 1, in the operation of taking a proof in ink on said prQo-f'shcet, or transparent sheet;

Fig. 7 is a similar view in side elevation, showing the transparent sheet of Fig.2 2 havingthe'image in ink thereon on one side thereof, hnt witli the other side in contact with the sensitized"film'ceated surface of tl're metallic make-ready overlay plate or sheetshown in Fig. 3, in. the process of printing the image on the sensitized surface or coating of said make-ready overlay plate by means of rays of light passing through. the transparent sheet;

Fig. 8 is a similar view in side elevation,

"showing the metal-lie. make-ready overlay plate or sheet of Fig 3 in eontactz wieh the l printing. surface at. the halfetonei or eliaotro t vpeplate shown in Fig. 4, as it would be in the process of applying pressure and impressing or making ready said half-tone plate, metallic printing plate or electrotype plate, by passing the metallic overlay plate into or against the half-tone plate, in accordance with my improved process;

Fig. 9 is a similar view in side elevation, showing a metallic make-ready overlay plate, such as that shown in Fig. 3 or Fig. 5 in contact with the printing surface of the half'tone or electrotype plate of Fig. 4, and with a mould identical with the metallic oven lay plate, but with the position of the image reversed and with the high-lights in the mould corresponding with the shadow-tones in the metallic overlay plate, and viceversa, in contact with the back of the half-tone or electrotype plate, shell or printing plate, in the process of applying pressure and impressing the make-ready overlay plate or sheet, or its image upon the half-tone or metallic printing plate;

Fig. 10 is an enlar ed detail view in section of a metallic ma e-ready overlay plate or sheet, such as that shown in Fig. 3 and in Fig. 5, showing a plurality of gradations, representing high-lights, middle-tones, and shadow-tones, respectively, in the etched surface of the metallic make-ready overlay plate;

Fig. 11 is an enlarged detail view in section, showing the metallic make-ready overlay plate in finished form and in contact with the printing surface of the half-tone, electrotype plate or metallic printing plate, and with the radations representing the high-lights, middle-tones and shadow-tones indicated diagrammatically, enlarged scale; and

Fig. 12 is a view in side elevation showing the original photo-engraving, with its inked face in direct contact with a makeready plate and in position to print an image in ink directly upon the latter.

In practicing my improved process, and treating and producing a corrected half-tone plate, electrotype plate, or metallic printing plate or plates in accordance with my process and invention, I provide an original photo-engraving 1, or similar picture, image or design made in any desired ordinary and well known manner, from which such halftone plate, electrotype plate, or metallic printing plate or plates are to be made.

I also provide a metallic make-ready overlay plate or sheet 3, formed of zinc, brass, copper, aluminum, or other suitable metal in plate or sheet form. This metallic makeready overlay plate is covered with a sensitized solution, coating of film 3' on one side thereof, said coating being made of suitable material which is sensitive to and adapted to be hardened or made more impervious to water by the action of rays of light, and may be in the form of a sensitized solution containing bichromate of ammonia, albuor on a greatly 1 men, or whites of-eggs, and water, all dissolved and intermlxed in the ordinary manner familiar to those skilled in the art of photo-engraving.

'I also provide an electrotype plate, halftone plate, or metallic printing plate 4 which may be made from the original photoen raving or subject l, in any desired or inary and well known or suitable manner, and is adapted to be completed and made ready and perfected by and in accordance with my improved process. whereby such printing plate will have what is commonly known as a make-ready em bodied in the metallic printing plate and its printing surface, when the plate is completed.

In practicing my improved process and invention in the manner which will be herein first described, I also provide a thin sheet 2 of suitabl flexible sheet material or printing paper, such, for example, as tissue papen onion skin paper, waxed paper, or other sheet material such as celluloid, or other suitable material, which is already trans parent or adapted to be made transparent. The sheet 2-, when made of paper or simila material, may be made transparent, either before or after printing thereon, by saturating the same with Vaseline, lard, ordinary machine oil, or other suitable material.

I then ink the printing face of the original photo-engraving or sub ect 1 with a suitable coating of ink, which may be applied in the manner ordinarily employed in making a proof or print from a photo-engraving or printing plate.

I then, by preference, dust the sheet or inked image in the sheet 2 with a resinous powder, or powdered bronze or asphaltuni powder, or what is commonly known in the art as dragons blood powder.

I then make a proof, print, or imprint from the inked printing surface of the photo-engraving or subject 1 upon either the thin proof sheet or transfer sheet 2. to be afterward transferred to or printed upon the sensitized coated surface 3' of the metallic make-ready overlay plate or sheet 3'. or else, I make such proof from the inked printing surface of the original photo engraving or subject 1 directly upon said sensitized or coated surface 3 of the metallic make-ready overlay plate, or sheet In practicing my process in the manner which will be herein first described. in which the thin sheet 2, or sheet of transparent material is employed, I first take the proof on said sheet 2 from the inked printing surface of the original photo-engraving l, as already suggested, and then lay the thin sheet 2, or transparent sheet, upon and in contact with the sensitized coated surface 3' ofthe metallic make ready overla plate or sheet 3, but, by preference. with the inked side of the sheet 2 out of contact with said surface of the metallic plate has been etched awaysufliciently to form the required depressions and elevations or gradations in the metallic surface. These gradations correspond with or form. what may be termed the high-lights, middle-tones. and shadow-tones, respectively, in the,make ready overlay plate or sheet. The bottom gradations, or high-lights, in metal makeready overlay 7 plate, which constitute the deepest depressions in the surface of the plate, are thus thoroughly cleaned and etched to the :desired depth. Wherever the zinc or metallic surface of the late is exposed and not covered with in; or inked sensitized coating, throughout any portion of the design the metal is eaten away or etched away by the acid to the required depth, and the design or surface of the plate, Wherever it is covered withacid resisting ink and powder, is, of. course left with the ink covered metallic surface higher than the part that has been etched away.

I then wash oft all ink from the surface of the plate with benzine, turpentine, or other suitable liquid solullionor material.

After the ink has been thins washed oil the plate, the sensitized solution still remains on all parts of the plate, except the part that has'been etched by the action of the acid; but the part of the surtaceof the plate and of the image which has not been etched is still covered with the coating of sensitized solution even after the ink has been removed. In fact, the coating of sonsitized solution which new remains on the plate may be said to beonly on that part of the plate Where the image OF'POIZHOIIS of the image remains as a raised surface portion of the plate. A weak solution of muriatlc acid, -for example, a solution consisting of or con-' taining one part of murlatic acid to five parts of water-is then applied upon the.

middle-tone surfaces, dots, or middletone gradations, by means of a small brush. This application of muriatic acid removes the sensitized solution from the middle-tone surfaces or gradations, and leaves themetal surface of the middle-tone and high-light gradations exposed and clean.v V

The plate is then again immersed in a nitric acid solution, such as the nitric acid bath. already described, and. given a slightetch, while the sensitized solution is still covering and protecting and holding up the shadow-tone surfaces or gradations, and

7 also what is commonly called the dead metal surfaces. This etch is to bring down the middle-tone surfaces or gradations, andithe high-light surfaoesor gradations, but without effecting the shadow tone. surfaces or gradations. y I f The plate is then again washed with water, and is then again immersed in a vveak lacunae The metallic overlayor makerready plate is thenlaid in conitact with the printing side of the-,l1alif-toneplate,felectrotype plate. or

na'etalli'cprinting plate, said printing plate being supported uponla bed or table, or a vall of a suitable mold brother suitable sup port. And pressure is applied to the hacker GXPOSBdy'SldB of the metal make-ready plate. or to both the'make-ready plate and halftone or electrotype; plate. The printing plate and rmake irea dy plate or overlay are thus: pressedto gether With'such force as to cause an impression of the face of the metallic make-ready overlay plate to" be impressed upon or reproduced in and upon the printing side of the electrotype plate. This piressure may be applied in any (lesirail suitable' or ordinary manner, by means ofhydraulic pressure, or any suitable means for applying pressure known to the art to which this invention relates.

A metallic mold formed of lead or other suitable material fi', of identical'construction with the make-ready overlay plate.

already described, but with the high-lights and shadowtones ordepressions and eleva- ,tions reversed with respect to those of the overlay plate, above described, and with the position of the image corresponding with that of the original photo-engraving and original electrotype plate, is laid, when de sired, in contact with the back of the electrotype plate, While the metallic make-ready plate is iii-contact with the printing face of the electrotype plate, during the opera tion of applying pressure to impress the make-ready plate upon the printing face of the electrot pe plate. Such a mol 'may be made by making an impression of the overlay plate 3 in the face of asheet or plate of lead, or other suitable material; or it can be made in a similar manner to that in whichthe metallic m ka eadymor y Plate is made by tc inga plate tote-rm the mold 5'. In making such a mold byetching, a sheet of suitable ;flexible ln aterialf identical with the proof sheetQ; be provided and a' proof made thereon direct from the printing ea of the llO leases ,oniginal photo-engraving, and then the inked surface of the proof sheet is laid directly upon the surface of a metallic plate 5, and then removed, leaving an inked proof on the coated surface. And then the etching of the mold plate 5 is completed in substantially the same manner as the make ready overlay plate 3, already described, but leaving high-light surfaces and shadoW-tpne iurfaces in reversed relation to those of the metallic make-ready sheet. i

he original photo-engraving and the transparent proof sheet, as well as the overlay plate, half-toneplate. or electrotype printing plate, and mold, are all provided with series of suitable register marks 6. where y said Plates and sheet may he accurately positioned with respect to each other during the operation in which any two or more of said members are laid together in the practice of my improved process and invention.

And to further insure the proper registration of the make-ready plate and metallic printing plate, holes may be drilled through both and ins inserted through the holes. ind the holes and pins may also extend through the molds 5' when such a mold is .zsed.

What I have termed the high-lights, highlight dots, surfaces or gradations, the same being the deepest depressions, or gradations inthe face of the metallic make-ready overlay plate are indicated by the reference numeral '5; the middle-tones, middle-tone dots, surfapes, or depressions in said make-ready plate being indicated by the reference numeral 7; and the shadow-tones. shadow-tone dots, surfaces or depressions in said makecady plate, the same being the hi host and most prominent gradation or gratfatio ns in said make-ready plate, heing indicated by the reference numeral 8. And all of said high-light, middle-tone, and shadow-tone dots, surfaces or gradations are shown diafgrammatically in greatly enlarged magnified form, in Fig. 10, and also in Fig. 11 and inlcss exaggerated form in Figures 1 to inclusive. In said Figures 1, 2, l and 5, inclusire, the high-light tones, surfaces or gradations 6, are indicated in the image the moon, the middle-tones n iddie-tone gradation or gradations 7, by the snttace of the water and the sky, and the shadowiones, shadow-tone dots, or gradations by the image of the hills and tree. But in Fig.3 the high-lights or high-light; gradations and the shadow-tones or shadow-tone gradations are reversed, compared with the other Figures 1., 2, 4.- 5 as already described. in the sense that the hills represent the high-lights, or l-iigh-light gradation, and th moo i represents the shadow-tone surface or gradation in said metallic make-ready overlay plate. It should be noted that the make-ready overlay plate 3 is shown in Fig; a i its complilted form; while in Fig. 5 the metallic make-ready overlay plate 9 is shown as it would appear immediately upon printing a proof in ink directly upon the sensitized surface of said plate 9 from the inked surface of the ori inal photoengraving shown in Fig; 1, which may he doite whenever it is fo in'cl more desirabie; orin' other words, when 'the-ase'ei a ti ans parent proof sheet is to dispensed with.

Haying descrihed m impreaed process and invention as practiced in cases Where a transparent proof sheet, such as the sheet 2, is used, I will now describe the manner of racticing said process withont the use of such transparent proof sheet or transfer sheet, as follows:

A suitalile polished plate 011 sheet of Zinc orother suitaiile materiat'trom which a metallic make-readyp1ateoroverlayplate, or sheet 3 is to'bfe madefis providedt as- 5130mm Figs. 5' and 12, in which said plate or sheet is indicated by the referencenumerai The make-ready overlay plate or metallic sheet 9' is provided with a sensitized coating identical with the coating 3, already described. Instead' of using atransparent transfer sheet or proof sheet 2, the original photo-engravin is provided with a coatmg of ink ap lied to its printing surface'hy means of an inked rollier in the manner already described, and the inked image is printed in ink directly from the face of the'o-riginal image or photo-engraving 1 upon the sensitized coating3 on the metallic everlay plate or sheet 9. using the usual registering marks in order to insure the proper positioning of the plates relat' iye-ly to each other: y

The metallic make-ready overlay plate 9 with its sensitized coating asshown in" Fig. 5; is their printed liy being placed in an exposed position so as to receiyethe rays of light, from the sun, or other stiitahln source of light, for a suitable length of time, for examale, for about three minutes. as already escribed. Before exposing the coated plate to the re s light, however,

theinked surface is listed with dragons blood owcler or resinous pewdsrmr simiiar material" adapted to render theinke'd sur face more of he; or more imperv-ions to the action- 0' the rays at tight; The ink, inked image or outline on the sensitized coated surface or the make-ready overlay plate is then cleaned ofi with tur entine', benzine, or other suitable material saying the sensitized solution still on all parts of the coated side or surface ofthe late. Ft is then only necessary to proeeed in the same manner already descrihed, to the completiidn of the metallic make-ready overlay plate, and of the half-tone plate,

electrotype plate, or metallic printing plate, which, when completed, will embody a complete makeready in the body and printing surface of such half-tone plate, electroiype plate, or metallic printing plate.

It will be readily understood by those skilled in the art of photo-engraving that half-tone plates, electrotype plates, or other metallic printing plates made, and prodded with a make-ready in accordance with my improved process and invention, as herein described, are adapted for use either in one-color worlt, twocolor work, three- ('OlOl work, or four-color work, or in work requiring any desired color or combination of colors, or any desired number of printing plates to be used in the ordinary manncr in doing color work, or mul-ti-color rinting. And it will be readily understood t 121i, each half-tone plate, or metallic printing plate, to be used for such color-worl may be perfected or made ready in the manner hereinabove described.

And while I have referred to high-1i 'hts, middle-tones, and shadow tones, and rave refrained from referring to the various colors, or tones produced or employed in color-printing or multi-color work, it will be readily understood by those skilled in the art of photo-engraving that any desired color or tone may be employed upon any one or more of any desired number of half-tone plates, electrotype plates, or metallic printing plates, to be employed in colonprinting, or to be used in printing from one or any desired number of such printing plates successively upon the same surface, page, or sheet, or other object, in the process or art of color-printing.

For example: F or four-color printing, yellow, red, blue, and black may be usec, with a different printing plate for each color. For three-color work, yellow, red, and blue may be employed, with a separate and distinct printing plate made in accordance with my improved process and invcn tion, for each color, respectively.

And for. two-color work blue and orange, orblack and'orange, or any desired colors or tones, or dill'erent variations of colors, may be employed. 7

The herein described process is capable of being employed for making either flat or curved half-tone plates, elect-retype plates,

,or other metallic printing plates; and the plates which have been perfect-ed or pro vided with a make-ready embodied in the body and surface of the plate may be curved in any desired ordinary and well known or suitable manner, for example, by passing the same between suitable plate-bending rolls while heated to a suitable temperature ion bending, andafter the plate has been imPTBSSfQ made ready in accordance with my improved process, as above described.

I claim:

1. A process of treating half-tone plates, clcctrotype plates and other metallic rinting plates which comprises etching an image on the surface of a make-ready sheet corre spending with the image on the printing side of a metallic printing plate to be made ready, then forcing the etched surface of the make-ready sheet against the printing surface of such metallic printing plate by means of pressure, thereby impressing upon the printing surface of the metallic printing plate the image which is etched upon the surface of the nrake-ready sheet.

A process of treating half-tone plates, elcotrotype plates and other metallic printing plates whichcompriscs etching an image on the surface of a metallic make-ready sheet corresponding with the image on the printing side of a metallic printing plate to be made ready, but with the high-light surfaces on the make-ready sheet corresponding with the position of the shadow-tone surfaces on the metallic printing plate, and the shadow-tone surfaces on the make-ready sheet corresponding with the high-light surfaces on the metallic printing plate, then laying the etched surface of the make-ready sheet in contact with the printing side of the metallic printing plate to be made ready, then forcing the etched surface of the metallic make-ready sheet against the printing surface of the metallic printing plate. thereby impressing upon the printing surface of the metallic printing plate the image which is etched on the surface of the makeready sheet.

3. The process of treating half-tone plates, 7

electrotype plates and other metallic print ing plates which comprises etching an image on the surface of a metallic make-ready overlay sheet, said image corresponding with an image on the printing side of a metallic printing plate to be made ready, but having the high-light surfaces of the etched metallic make-ready overlay sheet in contact with the corresponding shadow-tone surfaces of the metallic printing plate and having the shadow-tone surfaces of the make-ready overlay plate in contact with the high-light surfaces of the metallic printing plate, and then forcing the etched surface of the metallic make-ready sheet against the printing surface of the metallic printing plate by means of pressure, thereby impressing upon the high-light surfaces on the printing plate the impression of the corresponding surface portions of the image etched upon the metallic make-ready overlay plate.

4. The process of treating half-tone plates, electrotype plates and other metallic printing plates which comprises etching an image on the surface of a metallic make-ready sheet corresponding with the image on the printing side of a metallic printing plate to be op elated upon, but with elevated surface portions of the make-ready sheet in contact with depressed surface portions of the metallic printing plate and depressions in t'heetched surface of the make-ready sheet in contact with elevated surface portions of the metallic printing plate, then forcing the etched qurface of the malted-early sheet against and into the surface of the metallic printing plate thereby impressing upon the printing surface of the metallic piiinting platethe surface gradations on the opposed surface'ot the etched metallic make-ready sheet.

4), A process pf tr'eatin half-tone plates, elcctrotype plates and ot'l i er metallic print ing plates, ivhich comprises coating. 21 metallic make-ready placing over the coatedsurface of such malicreadgy sheet an image, and exposing the coated plate and image to the action of rays of'light while the image is between the coated surface and the source of light, then developing and etching the image in the metallic surface of the make-ready sheet, and then bending and correcting the printiiiglsurl ace of a metallic printing plate by pressing the etched sinitace of the metallic' make-ready sheet in Contact and bcnding engagement with said P ing u facea.

i 6-; A p 'o es tr ating half-hope pla es ele ,t-rotyp'e plates and; other metal-lie printin nla't iihi i il se ing a m tal lie make-ready sheet with a, coating fann d o ma tenance: ad'a .t d t be afictedlby the actiono f rays of light, plac ing over the coated surface of such makel 'eady sheet an image and'eigposing the coated plateand'iinage to the action of rays of lkght while the image is between the coated sur ace and the source of light, Mien-developing. and

' etching the image the metallic surface of the makemead} sheet, then laying the etched snrfiace of th make-ready sheet in contact iiitl P i g ii oi" me allic pri ting p a b opera ed upon, h e for ing he etched surface of the metallic make-ready sheet against the printing surface of the-metal l pla t ng pla h eby lmi ressing'iln on the printing surface of the 1netallic'printing plate the impression ofthe etched surface of themakc-ready sheet,

T, A process of treati'nQlial'f tone plates, elect-rotype plates and at 181 metallic printing plates, which comprises coating in metallic made-ready sheet with a coating. formed of: a sensitized solution. adaptedi to' be a f fected by the action of rays of light, placing upon the coated surface. of such make.- r a y h t an m ge in ink a exn s a' the coatedv sheet and to the action of rays of light, developing the coated sheet in A sheet with a coating i? formed of a sensitized solution adapted to he alfected by the action of of ugh-r,

water, thereby bringing out the covered image by removing the relatively soft m1;- prot'ected ortions of the sensitized coating wherever-the same has not been affected by the action of therays of light, leaving portionsof the metallic surface exposed, and leaving other portions of the sheet covered with said coating material and ink, then allowing the plate to dry, then etching said make-ready sheet, then placing the etched side of the makeready sheet in contact with the printing side of metallic printing plate to be operated upon, then forcing the etched surface of the metallic make; ready sheet against the printing surface of the metallic printing plate, thereby impressing upon the printing surface of the latter the impression of the etched surface of said make-ready sheet.

8. A process of treating half-tone plates, electrotype plates, and other metallic printing plates, which comprises coating a metallic make-ready sli'eet with a coating ofsensiti'zed'materi'al adapted to be affected by the action of rays of light, placinp upon the coated surface of the make ready sheet an image in ink, exposing the coated sheet and image to the action of rays of light, then developing the coated make-ready sheet by subjecting it to the action of water, thereloy removing relatively soft ink-protected portions of the sensitized coating from the metallic surface leaving portions of said metallic surface exposed, and leaving other portions of the sheet covered with saidcoating material, then allowing the plate to dry, then. etching said makeweady sheet by subjectin it to the action of acid, then placing the etched side of the make-ready sheet in contact with the rinting side of a metallic printingplalfe to lie operated upon, and then forcing the etched surface of the metallic make-ready sheet against the printing surface ofthe metallic printing plate, thereby impressing upon. said printing surface the impression of the etched surface of said maker-early sheet.

9i A process of' treating half-tone plates. electrotj p e plates or other metallic printing, plates, which comprises coating a metallic' make ready sheet with a coatin of sensijt'izedi material adapted to be a ected by the action of rays of light, placing upon the coated surface of the make-ready sheet an image in ink taken o h pr n ing u face of printing p at xp si g the coated shejelt and image to the action of rays of light, tl en developing the coated makereadgy sheet by subjecting it to the action of water, theneby removing relat'iveljv soft inkprotected portions of the sensitized coating from the metallic surface, and leaving other portions ofthe sheet covered with said coating material, tlien allowing the sheet to dry, H etcl i, by sulijecting it to the action of acid, then iii,

lie make-ready rnake-ready forcing the etched surface of the make ready sheet against the printing surface of the metallic printing plate, thereby impressing upon the printing surface of the latter the impression of the etched surface of said make-ready sheet.

10. A process of treating half-tone plates, electrotype plates, and other metallic printing plates, which comprises coating a metalsheet with a coating of sensitized material adapted to be affected by the action of rays of light, placing upon the coated surface of the make-ready sheet a transparent sheet containing an image formed of material which is light-resisting exposing the coated sheet and image to the action of rays of light, then developing the coated make-ready sheet by subjecting it to the action of Water, thereby removing rela- Lively soft portions of the sensitized coating from the metallic surface, and leaving other portions of the make-ready sheet covered with said coating material, then allowing the plate to dry, then etching said sheet, then forcing the etched surface of the make-ready sheet against the printing surface of a metallic printing plate to be operated upon, thereby impressing upon said printing surface the impression of the etchedsurface of said make-ready sheet.

11. A process of treating half-tone plates, electrotype plates, and other metallic printing plates, which comprises coating a metallic make-ready sheet with a coatin of sensitized material adapted to be a ected by the action of rays of light, placing upon the coated surface of the make-ready sheet an image formed oflight-resisting material, exposing the coated sheet and image to the action of rays of light, then applying a layer of acidresisting material to the surface of the sensitized coating on the make-ready sheet, then developing the coated make ready sheet by subjecting it to the action of water, thereby removing relatively soft portions of the sensitized coating from the metallic surface, and leaving portions of the make-ready sheet covered with said coating material, then allowing the sheet to dry, then etching said make-ready sheet by subjecting it to the action of an acid, and then forcing the etched surface of the make-ready sheet against the printing surface of a metallic printing plate to be operated upon, there- Jy impressing upon said printing surface the impression of the etched surface of said inalte-ready sheet. 7

12. A process of treating half tone plates, electrotype plates or other metallic printing plates, which comprises coating a metallic make-'ready sheet with a coating of sensitized material adapted to be affected by the action of rays of light, placing upon the coated surface of the make-ready sheet an image formed of light-resisting material, such, forexample, as ink, exposing the coated sheet and imageto the action of rays of light, then applying a'layer of acid-resisting material to the surface of the sensitized coating on the make-ready sheet, then de veloping the coated make-ready sheet by subjecting it to the action of Water, thereby re moving relatively soft portions of the sensitized coating from the metallic surface ofthe sheet and leaving other portions of the make-ready sheet covered with said coating material, then allowingthe plate to dry, then applying powdered material, such for example as dragons blood powder to the surface of the plate, then heating the plate and the coating material and powdered material on the plate, then etching the makeready sheet by subjecting it to the action of acid, then placing the etched side of the make-readysheet in contact with the printing side of a operated upon, and then forcing the etched surface of the metallic makeready sheet against the printing surface of the metallic printing plate.

13. A process of treating half-tone plates, electrotype plates or other metallic printing pla'tes,'which comprises coating a metallic make-ready sheet with a coating of sensitized materi l ad'apted to be afiected by the action of rays of light, placin upon the coated surface of'the make-rea y sheet an image in ink from the printing surface of a printing plate, exposing the coated sheet and ima e to the'action of rays of light, then app ying'a layer of acid-resisting material to the surface 'of the sensitized coating on the make-ready sheet, then developing the coated make-ready sheet by subjecting it to the action of Water, thereby removing relatively soft portions of the sensitized coating from the metallic surface of the sheet and leaving other portions of said sheet covered with coating material, then allowing the plate to dry, then applying powdered resinous material such as dragons blood powder to the surface of the plate, then heating the plate to melt and harden the powdered material to form an acid-resisting coating, then etching the sheet by subjecting it to the action of acid, and then forcing the etched surface of the makeready sheet against the printing surface of the metallic printing plate, thereby impressing upon said printing surface the impression of the etched surface of said makeready sheet.

'14 A process of treating half-tone plates, electroty e lates, or other metallic printing plates W ch comprises coating a metallic make-ready sheet with a coating of sensitized material adapted to be affected by the action of rays of light, placing upon the coated surface of the make-ready sheet an metallic printing plate to be.

image in ink taken from the printing surface of a printing plate, such, for example, as a photo-engraving, exposing the coated sheet and image to the action of rays of light. then applying a coating of ink to the surface of the sensitized coating on the make-ready sheet, the-n developing the coated make-ready sheet in Wa ter, thereby removing portions of the sensitized coating from the metallic surface of the sheet and leaving portions of said sheet covered with coating material, then allowing the plate to dry, then applying powdered resinous material such as dragons blood powder to the surface of the plate, then heating the plate to melt and harden the powdered material to form an acid-resisting coating, then etching the coated sheet by su bjecting itto the action of a solution containing nitric acid, thus forming the high-light surfaces in the form of depressions in the make-ready plate, and middle-tone surfaces in the form of less depressed surface portions of said plate. and said middle-tone surfaces and the relatively high shadow tone surfaces being left partially covered by acid-resisting material and by sensitized coating material, then removing all of the ink from the surface of the sensitized coating material and plate, then removing the sensitized coating material from the middle-tone surfaces by applying thereto a solution containing muriatic acid, thereby leaving the high-light surfaces and middle-tone surfaces of the metallic sheet exposed and in condition to be acted upon by acid. then subjecting the plate to the action of a solution containing nitric acid thereby lowering the high-light and middletone surfaces with respect to the shadowtone surfaces on which acid resisting material still remains. then washing the plate with water, and again subjecting itto the action of a solution containing muriat-ic acid, thereby removing all of the remaining sensitized solution. then again washing the sheet with water and again subjecting it to the action of a solution containing nitric acid to reduce the sharpness of the angles, then removing the acid resisting material covering the back of the make-ready sheet, and the nitric acid solution from the surface of the sheet, then forcing the etched surface of the metallic make-ready sheet against the printing surface of the metallic printing plate thereby impressing upon said printing surface the impression of the etched surface of said make-ready sheet.

15. A process of making make-ready sheets for use in treating half-tone plates, electrotype plates or other metallic printing plates, which comprises coating the metallic sheet with a coating of sensitized material which is adapted to be affected by the action of rays of light, then etching the coated sheet by subjecting it to the action of a solution containing nitric acid, thus forming high-light surfaces, and. middle tone surfaces, but leaving shadow tone surfaces par tially covered with acid-resisting material and by sensitized coating material, then re moving all of the ink from the surface of the sensitized coating material and plate, then removing the sensitized coating matcrial from the middle-tone surfaces by applying thereto a solution containing muriatic acid, thereby leaving the high-light sin-faces and middle-tone surfaces of the metallic sheet exposed and in condition to be acted upon by acid, then subjecting the plate to the action of a solution containing nitric acid, thereby lowering. the highlight and middle tonesurfaces ivith respect to the shadow-tone surfaceson; which acid-resisting material is still allowed to remain. then washing the plate with 'watenthen again subjecting it tothe action of asolution con t aining muriatic acid, thereby removing all of the remaining sensitized solution. then washing the sheet with water and again sub jecting it to the action of a solution containing nitric. acid to round off the angles. then wash off the nitric acid solution. an then removing the acid-resisting material covering the back of the sheet.

16. A process of treating half-tone plates. elcctrotype plates and other metallic printing plates, which comprises coating a metallicunakc-ready sheet with a coating forme of a sensitized solution adapted to be affected by the action of rays of light, placing in juxtaposition to the coated surface of such make-ready sheet an image in ink and exposing the coated plate and image to th action of rays of light, then developing and etching the image in the metallic surfac of the make-ready sheet. said image corresponding with an image on the printins side of a metallic printing plate to be operated upon, but having the high-light surfaces of the etched metallic make-ready sheet in positions corresponding with the shadow-tone surfaces of the metallic printing plate, and having the shadow-tone surfaces of the make-ready plate in positions corresponding with the high-light surfaces of the metallic printing plate, and then forcing the etched surface of the metallic make ready sheet against the printing surface of the metallic printing plate, thereby impressing upon the high-light surfaces of the printing plate the impression of the opposed surface portions of the etched side of the metallic make-ready plate.

17. A process of treating half-tone plates. electrotype plates and other metallic printing plates, which comprises coating a metallic make-ready sheet with a coating formed of a sensitized solution adapted to be affected by the action of rays of light, placing over the coated surface of such make-ready sheet a transparent sheet containing an image and exposing the coated plate and image to the action of rays of light while the image is between the coated surface and the source of light, then developing and etching the image in the metallic surface of the make-ready sheet, then laying the etched surface of the make-read sheet inccntact with the printing side 0 a metallic printing plate to be operated upon, then forcing the etched surface of the metallic makeready sheet against the printin surface of the metallic printing plate, t ereby impressing upon the printing surface of the metallic printing plate the impression of the etched surface of the make-ready sheet.

18. A process of treating half-tone plates, electrotype plates, and other metallic printing plates, which comprises coating a metallic make-ready sheet with a coating of sensitized material adapted to be affected by action of rays of light, then developing the coated make-ready sheet, then etching said make-ready sheet by subjecting it to the action of acid, then laying the etched surface of the make-ready sheet in contact with the printing side of a metallic printing plate to be operated upon, then forcing the etched surface of the metallic make-ready sheet against the printin surface of the metallic printing plate, t erehy impressing upon the printing surface of the metallic print ing plate the impression of the etched surface of the make-ready sheet.

Si ed at Chicago, in the county of Cook and tate of Illinois this 22nd day of J ulv.

' JULIUS DICKERT. 

